A portable belt sander includes a drive pulley, a driven pulley and an endless polishing belt mounted over the drive and driven pulleys. Rotation of the drive pulley provides a circulating movement of the belt so as to polish a surface of the workpiece.
A conventional drive pulley 102 is shown in FIGS. 12 and 13. The drive pulley 102 includes a drive shaft 107 drivingly connected to a motor (not shown), a base section 108, and an outer section 109. The base section 108 is coupled to the drive shaft 107 and is made from rigid or high hardness material such as aluminum and a resin. The outer section 109 is covered or crowned over the base section 108 and is made from a soft or low hardness material such as a rubber having high frictional resistance so as to avoid slippage of the polishing belt with respect to the outer section 109 to ensure circulating movement of the endless belt. Such conventional structure is shown in laid open Japanese patent application publication No. 2000-280157.
The outer section 109 made from the rubber is fixed to the outer peripheral surface of the base section 108 by baking (forming) with employing expensive two-part adhesive. Prior to baking, various processes must be required such as degreasing an adhesion surface of the base section 108, drying the surface, coating a first adhesive, drying the first adhesive, coating a second adhesive and drying the second adhesive. Such preliminary processes require almost one day, and rubber forming requires about 10 to 20 minutes. Accordingly, a resultant drive pulley 102 becomes expensive.